fma(3) [opendarwin man page]

FMA(3)							   BSD Library Functions Manual 						    FMA(3)

NAME

     fma -- multiply and add, then round

SYNOPSIS

     #include <math.h>

     double
     fma(double x, double y, double z);

     float
     fmaf(float x, float y, double z);

DESCRIPTION

     The fma() and fmaf() functions compute (x*y)+z, rounded as one ternary operation: they compute the value (as if) to infinite precision and
     round once to the result format, according to the current rounding mode.

SPECIAL VALUES

     fma(x, y, z) returns a NaN and optionally raises the "invalid" floating-point exception if one of x and y is infinite, the other is 0, and z
     is a NaN.

     fma(x, y, z) returns a NaN and raises the "invalid" floating-point exception if one of x and y is infinite, the other is 0, and z is not NaN.

     fma(x, y, z) returns a NaN and raises the "invalid" floating-point exception if x times y is an exact infinity, and z is also an infinity but
     with the opposite sign.

SEE ALSO

     fdim(3), fmax(3), fmin(3)

STANDARDS

     The fma() and fmaf() functions conform to ISO/IEC 9899:1999(E).

BSD
								   July 24, 2003							       BSD

fma(3M) 						  Mathematical Library Functions						   fma(3M)

NAME

       fma, fmaf, fmal - floating-point multiply-add

SYNOPSIS

       c99 [ flag... ] file... -lm [ library... ]
       #include <math.h>

       double fma(double x, double y, double z);

       float fmaf(float x, float y, float z);

       long double fmal(long double x, long double y, long double z);

DESCRIPTION

       These  functions compute (x * y) + z, rounded as one ternary operation. They compute the value (as if) to infinite precision and round once
       to the result format, according to the rounding mode characterized by the value of FLT_ROUNDS.

RETURN VALUES

       Upon successful completion, these functions return (x * y) + z, rounded as one ternary operation.

       If x or y are NaN, a NaN is returned.

       If x multiplied by y is an exact infinity and z is also an infinity but with the opposite  sign,  a  domain  error  occurs  and	a  NaN	is
       returned.

       If one of x and y is infinite, the other is 0, and z is not a NaN, a domain error occurs and a NaN is returned.

       If x*y is not 0*Inf nor Inf*0 and z is a NaN, a NaN is returned.

ERRORS

       These functions will fail if:

       Domain Error    The value of x*y+z is invalid or the value x*y is invalid.

		       If  the	integer  expression  (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception will be
		       raised.

       Range Error     The result overflows.

		       If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the overflow floating-point  exception  will	be
		       raised.

USAGE

       An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
       fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception  has  been  raised.  An  application  should
       either examine the return value or check the floating point exception flags to detect exceptions.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       feclearexcept(3M), fetestexcept(3M), math.h(3HEAD), attributes(5), standards(5)

SunOS 5.11							    12 Jul 2006 							   fma(3M)